Blubbing at TV ads one minute, struggling to keep your lunch down the next? Yep… that’ll be those pesky pregnancy hormones.
By Claire Chamberlain
Pregnant and feeling a little peculiar? After the excitement of seeing those parallel blue lines appear on the little white pregnancy test stick you peed on, it can be a bit of a shock when rampaging chemicals (AKA pregnancy hormones) start to play havoc with everything, from your mood, to your skin, to your digestion.
Want to know what to really expect when you’re expecting, courtesy of your hormones? Mrs Pisal, consultant gynaecologist and obstetrician at London Gynaecology gives us the lowdown on the emotional and physiological changes you might experience, thanks to the six key pregnancy hormones:
- When?This appears on the eighth day after ovulation, and is one of the earliest secreted hormones. It can usually be detected five to six days after ovulation, but definitely by ten days after.
- Peaks:This hormone doubles every 48 hours in early pregnancy, hitting its maximum level at around eight to ten weeks.
- Function:HCG supports the corpus luteum (essential for conception to occur and the pregnancy to last).
- Side effects:Headaches, irritability, restlessness, fatigue, insomnia, nausea and vomiting (the dreaded ‘morning sickness’) and fluid retention.
- When?This is produced from pre-pregnancy until about 10 to 12 weeks from the follicle area in the ovary (corpus luteum), where the egg is released from. The placenta and fetal adrenal gland then produce it until term.
- Peaks:In the late third trimester.
- Function:Oestrogen prepares the uterine lining for implantation of the embryo. It is also helpful in preventing miscarriage and is a catalyst for chemical changes for growth, development and energy in the baby. Oestrogen steps up blood circulation, regulates the production of other key hormones and promotes breast engorgement in early pregnancy.
- Side effects:Increased blood flow to mucous membranes can cause headaches, postnatal drip and nasal congestion. Some areas of your skin my also experience hyperpigmentation, especially the areola and along the midline on the abdominal wall.
- When?This is produced from pre-pregnancy until about 10 to 12 weeks from the follicle area in the ovary (corpus luteum), where the egg is released from. The placenta then produces it until term.
- Peaks:In the late third trimester.
- Function:To prepare the uterine lining for implantation of the embryo. It also suppresses the mother’s response to foetal antigens, helping to prevent the mother’s body rejecting the embryo, which can result in miscarriage or premature labour.
- Side effects:Gastrointestinal discomfort, including indigestion, heartburn, constipation and bloating; aching hips, pubic bone and back; bleeding gums; and increased sweating.
- When?This is produced by the corpus luteum and the placenta from early through to late pregnancy.
- Peaks:This hormone peaks at 14 weeks and then again around the time of delivery.
- Function:Relaxin helps to prepare the uterine lining for implantation of the embryo; assists uterine growth to accommodate your growing baby; helps to prevent premature labour; assists cervical ripening, important to facilitate labour; relaxes pelvic ligaments in preparation for birth; and reduces insulin resistance.
- Side effects:Due to the fact it relaxes ligaments, relaxin can cause joint and ligament pain, and backache. It can also cause heartburn, as it relaxes the smooth muscle and sphincter of the stomach, enabling acid to flow back up into the food pipe.
- When?This is produced by the hypothalamus and is released from the pituitary gland in the mother’s brain throughout pregnancy.
- Peaks:Oxytocin levels rise from the first to the third trimester, and fall during the postpartum period, after birth.
- Function:This stimulates the ripening of the cervix, leading to successive dilation during labour. Along with other hormones, it causes the release of prostaglandins, which play an important role in ripening of the cervix. Sometimes referred to as the ‘love’ hormone, this is also the chemical that helps you bond with your newborn.
- Side effects:This can cause irritability, Braxton-Hicks and excessive hair growth.
- When?This starts to be secreted in early pregnancy.
- Peaks:There is a sustained rise in prolactin, which continues after birth.
- Function:Prolactin is responsible for the enlargement of the mammary glands and milk production, which normally starts when levels of progesterone fall at the end of pregnancy, and a suckling stimulus (your baby!) is present.
- Side effects:Irregular periods or cessation of menstrual periods.