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Your Pregnancy Guide

Your Pregnancy Guide

A complete guide to your pregnancy, to coincide with your consultations and scans with Dr McKenna. We outline details on your baby's growth, your body and symptoms to look out for.

Scroll down to see your complete pregnancy guide.

A complete guide to your pregnancy, to coincide with your consultations and pregnancy scans with Dr McKenna. We outline details on your baby's growth, your body and symptoms to look out for.

Traditionally, medics use the first day of the last menstrual period as the marker of getting pregnant but the actual conception does not occur until the beginning of the third week. This means that the baby’s real age is two weeks behind that of the gestational age. Dating a pregnancy using the last menstrual period can lead to difficulties if the periods have been irregular or if the woman has conceived within 3 months of stopping the contraceptive pill. Dates are clarified by ultrasound examination.

Hopefully, you will have commenced folic acid supplements for at least three months before conception. You will continue it for the first 12 weeks of your pregnancy. Folic acid supplementation reduces the risk of a baby with spina bifida by a factor of ten. If you haven’t already, it’s a good time to stop smoking and to stop drinking any alcohol.

Some high risk pregnancies require prescription medication from the day the pregnancy test is positive. These medications include low-dose aspirin, progesterone supplements and heparin injection to thin the blood. A pre-pregnancy discussion so a plan for the pregnancy is in place is invaluable in these circumstances.

Your Body

Nausea and vomiting in pregnancy (NVP) is very common. Paradoxically, however, 30% of women have no nausea at all. Thankfully, the lack of nausea in pregnancy does not predict a poor outcome for the pregnancy. The term “morning sickness” is also a misnomer. Sickness can occur throughout the day, often in the evening. Eating small amounts at a time, ginger, acupressure and acupuncture can all help alleviate the feelings of nausea. If medication for nausea is required, rest assured that any medication prescribed in pregnancy will be safe for the baby.

Women often describe breast tenderness at this stage. This is normal and necessary to prepare your body for breast-feeding. Some women report that their breasts grow by a whole bra-cup size in pregnancy.

Constipation is very common in pregnancy. The hormones of pregnancy make the bowel sluggish. Eating a high-fibre diet and drinking lots of water can help with constipation. Rarely, laxatives need to be prescribed to help with constipation in pregnancy.

Bright red vaginal bleeding is common but not always normal at this time. The bleeding is called a threatened miscarriage and it often settles on its own.  Sadly, about one in four pregnancies fail at about this stage. Bleeding with period-like cramps might suggest a miscarriage is imminent.

Bleeding with right-sided or left-sided pelvic pain, feeling faint or rectal pain on opening your bowels might suggest an ectopic pregnancy. Any of these symptoms would require emergency assessment at your local maternity hospital.

Thankfully, once a strong heart beat is seen in the baby on ultrasound scan, the risk of miscarriage is significantly reduced.


Your Baby

Your baby measures about 5mm long at 7 weeks. A strong heartbeat can be seen on scan at this time. The baby’s major organs are forming at this time and its brain cells are being generated at a rate of 100 per minute!


Your Body

Hopefully, any nausea and vomiting will be easing at this stage as will the tiredness that is often associated with early pregnancy.

By week thirteen it is possible to feel the growing womb on abdominal examination, just above the pubic bone. The linea negra may appear at this time. The linea nigra is a pigmented line on your tummy that runs from your pubic bone to the umbilicus. It is a normal finding.

You may feel a burst of energy at this time and exercise is very important for your general wellbeing. Low-impact aerobic exercise is best.

It is also a good time to start your pelvic floor exercises. These will help strengthen the pelvic muscles in preparation for labour and birth.


Your Baby

Your baby measures about 7cm long at 13 weeks. The baby is now fully formed and the umbilical cord is fully functional. The baby can curl fingers and toes and clench eye muscles. Vital organs can now perform complicated tasks. The liver is producing bile and the kidneys are now secreting urine. Baby girls have their ovaries and baby boys are developing their testes.


Your Body

By week 17, the top of your womb should be palpable half-way between your pubic bone and umbilicus. The round ligaments hold your womb in place in your pelvis. Round ligament stretch is often felt at this stage of pregnancy. It is often described as “stitch”. It is normal and it often gets easier after 22 weeks.

An increased need to urinate is a perfectly normal part of pregnancy, even 2-3 times through the night.

You might start to feel flutters at this stage or quickenings. This is possibly due to the increased blood flow to the uterus.

You may also start to experience a thin, milky vaginal discharge from the vagina called leukorrhoea. This happens as the pH in the vaginal changes in pregnancy. This is normal and it helps keep the birth canal free of infection.


Your Baby

Your baby measures about 12cm long at 17 weeks. The baby has a growth spurt around this time. This may also be the first time that you feel your baby move.  Body fat is beginning to develop. The circulatory and urinary systems are fully formed and the baby will be inhaling and exhaling the amniotic fluid. The baby’s hearing is also forming at this time and the baby can be seen responding to external noises.



Your Body

By week 21, your womb should be easily palpable at your umbilicus. You may be feeling fetal movements by now. These movements feel more like kicks than flutterings.

Your blood volume increases by 50% in pregnancy and your blood pressure will be at its lowest at this stage. Women often describe being breathless and light-headed at this time. This is normal. Weight gain is usually about 250 grams per week from this point on.

Some women start to experience colostrum leaking from their breasts. This is the first form of milk that your body produces. It is normal.

You may also be starting to notice the appearance of stretch marks on your belly, legs and breasts. Unfortunately, stretch mark creams do not prevent their formation.


Your Baby

Your baby measures about 27cm from head to heel at 21 weeks. The digestive system is fully formed and the baby is able to swallow amniotic fluid. The bones are starting to harden and the eyes are fully formed.

If the fetus is female, the uterus is fully formed and the vaginal canal is starting to develop and form. If the fetus is male, the testicles are formed and are beginning to descend from the abdomen.

Your Body

Heartburn is often described at this stage. It occurs for two reasons. Firstly, the pregnancy hormones relax the muscle at the lower end of the oesophagus so acid can escape from the stomach up into the oesophagus. Secondly, the pregnant uterus pushes the stomach up into the diaphragm, forcing acid into the oesophagus. Heartburn can be “cured” by prescribing medicine to stop acid production. These medications are perfectly safe in pregnancy.

Restless Leg Syndrome (RLS) is often described at this stage. This is characterised by a tingling in the legs and an urge to move the legs. Although the symptoms are uncomfortable, they are not harmful.

Poor sleep and snoring is reported by many women. It can be made worse by not being able to find a comfortable position in bed. Daily exercise and fresh air may help with sleeping problems and sleeping on your side with a pillow between your legs may help find a comfortable sleeping position.


Your Baby

Your baby measures about 35cm from head to heel at 25 weeks. Body fat continues to form and build up during this week. Sensory development also continues and the fetus is able to respond to touch. The lungs continue to develop and start to produce surfactant. Surfactant is a chemical that will allow the lungs to expand after birth. The baby’s eyes, that were previously fused, have started to open.

A baby that delivers at 25 weeks would be considered to have reached the age of viability. However, many babies would still die at this stage and of those that survive, the risk of some form of handicap would be high.

Your Body

Backache is a common pregnancy-related symptom during the third trimester. The pregnancy hormones are relaxing your pelvis in anticipation of labour and delivery. They also relax the joints in your back, causing backache. Many women find physiotherapy and massage beneficial.

Varicose veins are very common at this stage. They are common in the legs but also in the vulva and vagina. Haemorrhoids and piles are varicose veins in your anus.  Maintaining good blood flow by drinking plenty of water and taking gentle exercise can both help to alleviate the symptoms.

Digestive discomfort such as trapped wind becomes more frequent during this stage of pregnancy. Digestive problems can also lead to problems sleeping. Avoiding eating too close to bedtime may help with this.


Your Baby

Your baby measures about 39cm from head to heal at 29 weeks. Fetal growth is likely to triple between this week and birth at full term, although fetal length will only increase by a relatively small amount. Bones continue to harden and approximately 200mg of calcium are deposited into the skeleton each day. The fetus is now less able to turn easily and movements tend to be smaller than in previous week.



Your Body

If the baby has dropped into your pelvis, you may find that some of your pregnancy symptoms have eased somewhat. These would include digestive discomfort and breathlessness.

You may start to experience Braxton Hicks contractions. By definition, these are painless contractions and a hardening of the uterus. In practice, some patients describe these contractions as painful, leading to a diagnosis of an Irritable Uterus. The presence of these contractions do not predict an earlier delivery.

Some women experience swelling in their lower legs and ankles during the latter stages of pregnancy. It is made worse in warm weather. You should not reduce your fluid intake if you do experience swelling in legs or fingers. If you notice a sudden increase in swelling of your legs, hands or face, you should see your GP or Obstetrician as it could be a sign of pre-eclampsia.


Your Baby

Your baby measures about 44cm from head to heal at 33 weeks. You would be expecting the baby to be head down at this stage. If it is head down, it would be unlikely to move from this position during the rest of the pregnancy.

The baby’s organs are fully formed at this stage, and its immune system continues to develop. If the baby were to be born at this stage, long term neurological development should not be affected.


Your Body

Some women find a bumpy itch rash appears on their tummy at the later stages of pregnancy. This is not harmful to you or your baby. Antihistamines are safe in pregnancy should the itch become intolerable.

Some women experience a tingling in their hands and fingers, often associated with weakness.  It is called carpel-tunnel syndrome and it disappears after delivery.

You may find that your gums are more sensitive and bleed more easily. This is normal. During pregnancy, you are more prone to gum disease so a trip to your dentist is advised.

You will need weekly check-ups from now till delivery with your GP/Obstetrician.


Your Baby

Your baby measures about 46cm from head to heal at 35 weeks. Body fat has accumulated sufficiently so that the baby can control its body temperature. The amniotic fluid volume starts to decrease to allow the developing  fetus space to grow. Fetal movements are likely to be less dramatic now as space in the uterus is becoming more limited.


Your Body

Term, by definition, is anything from 37-42 weeks’ gestation. Plenty of rest is essential. The Braxton Hicks contractions may increase and the pressure in your pelvis may increase. Walking may become more difficult.

You will have weekly antenatal appointments until delivery. If an elective caesarean section is planned, this is usually carried out at 39 weeks’ gestation. If spontaneous labour has not occurred by 41 weeks, induction of labour will be offered.

You may have a “show”. A show is a bloody-mucousy discharge. Sometimes it’s more bloody than mucousy, sometimes more mucousy than bloody. A show is normal and it may predict that labour is imminent.

A vaginal exam from your obstetrician or midwife can help predict how close spontaneous natural labour may be. It will also give you and your obstetrician good information as to how easy it would be to induce your labour should it be indicated or indeed requested.

Patients often say that they won’t know what a true labour-contraction pain will feel like. A significant pain would waken you from your sleep or prevent you sleeping if you were experiencing them.

Waters breaking, or rupture of membranes, usually occur in labour. In one woman in ten, the waters break before the onset in labour. You get no warning of this and if your waters break it’s important to get to hospital as soon as possible as labour could be close and there’s a small risk of infection.


Your Baby

Your baby can measure up to 50cm from head to heal at term. 95% of babies at term are head down. Fetal growth continues until delivery. The placenta is still fully functioning supplying nutrients and antibodies that will help strengthen the baby’s immune system. Fetal movements are becoming more limited due to restricted space in the womb. Kicks will likely be reduced but the baby should still wriggle and squirm. Ten movements in 12 hours should still be felt. If the baby doesn’t move 10 times in twelve hours, don’t go to bed on a quiet baby. A call to the hospital is advisable and the midwives may suggest attending for a fetal heart rate tracing.

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